Several variations of header units are commonly used in combines or harvesting machines for harvesting row crops such as corn and cotton. One such header unit is a corn head with fixed spacing between the row units. Several other corn heads allowing variable spacing between the row units have also been developed. However, both fixed and variable spacing corn heads are designed to only efficiently harvest corn planted in rows having a row width of greater than 20 inches.
Recent research on the spacing of the corn rows has indicated special benefits for narrower row spacings that are 12-16 inches apart. In addition to the obvious increase in yield and crop population, these benefits include improved erosion control and better weed control. The narrower rows also require less chemicals and pesticides per unit of yield, thereby benefitting the environment.
Unfortunately, the spacing between adjacent row units of existing header units are not designed to harvest rows having a spacing of 16 inches or less. Moreover, modifying the spacing between adjacent row units of existing header units to effectively harvest rows having spacing of 16 inches or less is difficult, if not impossible. The ability to construct row units of existing headers more closely together for row widths of less than 20 inches is inherently limited by the size of row unit components. For example, each individual row unit typically includes two gatherers adapted for moving corn ears or other harvested crop to a rear of the header unit. The conventionally required spacing of the gatherers prevents row units from being constructed closer together for harvesting rows of crops having a spacing of less than 20 inches. As a result, existing header units have sub-optimal harvesting efficiency when harvesting narrow rows.